Hydraulic preload adjust on the rear shock

[persempre907]

Hi everybody.
A good friend of mine, Alessandro, here as "nojapan", asked me to show on the forum a very interesting mod to the rear shock.

During the overhauling of the rear shock of his Paso 750, he thought to do an upgrade to add a remote hydraulic adjust on the shock.

First, it needs to disassemble the shock and remove the piston which separates air and oil.


Now, it musts to enlarge the hole where is located the air-valve, near the highest fixing point of the shock and screw a banjo bolt on it .


So, it needs to connect the hose to the reservoir, fill the body of the shock with oil and bleed the air from the reservoir (he recommends do not inflate air inside first) inflating and then deflating the air, so that all the air bubbles can get away.

Then, it needs to reassemble the shock and remove the oil exceeding (he used 2 parts of SAE 2.5 and 1 SAE 5 oil).

The reservoir has to be inflated about 6-10 atm (he's still testing about the best setting).

The result is very interesting.


He used a Suzuki GSX750R rear shock, bought on ebay for only €. 20.
It has a 16mm. stem, when the Marzocchi has a 14mm. stem, and the alu body is larger than the Marzocchi Duo-Shock, so that the valves are larger, too.
Such mods allow to have a cooler operation but, above all, an hydraulic remote preload adjust on the shock!!!
He spent €. 15 for the oil and €. 20 for the banjo bolt and the braided hose.

Ciao

[desmodave]

wow! this is really intelligent of you fella specially for english roads where the dukes are known for rigid suspesion, I see the adjusters are right down on your photos no need for bending down with a c-spanner now eh? whats the resulting suspension like then?.......desmodave uk.

[persempre907]

Yes, no need of spanner.
About the results, the friend of mine is still testing the shock.
I hope he will tell us something about personally.
Ciao

[JWilliam]

Did your friend have to use any special tools to dismantle the shock body? I had a quick go last year but when the base collar woudn't budge I didn't try further.

[persempre907]

I will ask him and let you know.
Ciao

[persempre907]

I have asked about your question.
First of all, a rectification: only the reservoir is from a Suzuki's shock.

To take the shock apart he has employed this tool:
http://www.beta-tools.com/catalog/artic ... __filters_
Besides, to unscrew the upper ring it needs to warm the body of the shock. Not too much to avoid damages to the dust seal.

Ciao

[Finnpaso]

Frankie, You will be "Paso guru" soon, as i have noticed, that You know already many things how they function...

[persempre907]

Frankie, You will be "Paso guru" soon

...only with the words and not by the facts .
Ciao

[nnnnnnorman]

i have been trying to source a replacement duo shock for my 906. the top eye mount on mine is cracked. i need either a complete shock to use or one to get rebuilt or just a replacement top eye mount to add to my shock. or is there another suitable shock that fits a 906?

[Mc tool]

Hi nnnnnnorman Im pretty sure that I have read here ( somewhere ) that someone succsessfully welded ( or had weded for them ) that cracked top mount , and I know of another that has never been repaired and as got no worse

[higgy]

A photo of my formerly cracked (and subsequently repaired) shock can be found at:

http://docs.google.com/View?id=dgv8c3qz_342cffkbhf8



I must stress that there was no play whatsoever in either of the bushes (pretty good after 65,000 miles). The small amount of play was entirely due to the crack.


Courtesy of Paso904